Sorry I didn't respond to your messages...I wasn't able to get back on the board until today. I will have a kitty window, but my problem is how to connect it to the cat enclosure since the top of the enclosure will be quite a few feet lower than the window. I need some type of enclosed stairs, something so they don't have to do a vertical drop from the window down a whole story. That's my biggest dilemma other than building on a sloping back yard...The "roof" of the enclosure will be some type of chicken coop wire...my kitties can climb way up in trees (they were born outside). If I don't have it completely enclosed they will definetely escape!